Question: Solve for $x$ : $2x + 9 = 7x + 10$
Solution: Subtract $2x$ from both sides: $(2x + 9) - 2x = (7x + 10) - 2x$ $9 = 5x + 10$ Subtract $10$ from both sides: $9 - 10 = (5x + 10) - 10$ $-1 = 5x$ Divide both sides by $5$ $\dfrac{-1}{5} = \dfrac{5x}{5}$ Simplify. $-\dfrac{1}{5} = x$